001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v1.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014package ch.qos.logback.core.joran.conditional;
015
016/**
017 * <p>A condition evaluated during Joran conditional processing.</p>
018 *
019 * <p>Implementations of this interface encapsulate a boolean test that
020 * determines whether a conditional block in a Joran configuration should
021 * be processed.</p>
022 *
023 * <p>Typical implementations evaluate configuration state, environment
024 * variables, or other runtime properties.</p>
025 *
026 * @since 0.9.20
027 * @author Ceki G&uuml;lc&uuml;
028 */
029public interface Condition {
030
031    /**
032     * Evaluate the condition.
033     *
034     * @return {@code true} if the condition is satisfied and the associated
035     *         conditional block should be activated; {@code false} otherwise
036     */
037    boolean evaluate();
038}